Clad plate for forming interposer for semiconductor device, interposer for semiconductor device, and method of manufacturing them

ABSTRACT

A clad plate for forming an interposer for a semiconductor device which can be manufactured at low cost and has good characteristics, an interposer for a semiconductor device, and a method of manufacturing them. Copper foil materials ( 19, 24, 33 ) forming conductive layers ( 10, 17, 18 ) and nickel plating ( 20, 21 ) forming etching stopper layers ( 11, 12 ) are formed and pressed to form a clad plate ( 34 ) for forming an interposer for a semiconductor device. Thus, a clad plate ( 34 ) for forming an interposer for a semiconductor device is manufactured. The clad plate ( 34 ) is selectively etched to form a columnar conductor ( 17 ), and an insulating layer ( 13 ) is formed on the copper foil material forming a wiring layer ( 10 ). A bump ( 18 ) for connection of a semiconductor chip and the wiring layer ( 10 ) are formed on the opposite side to the side on which the columnar conductor ( 17 ) is formed. Thus, an interposer for a semiconductor device is manufactured.

The present application is the national stage under 35 U.S.C. §371 ofinternational application PCT/JP00/03746, filed Jun. 9, 2000, whichdesignated the United States, and which application was not published inthe English language.

TECHNICAL FIELD

This invention concerns an interposer-forming clad plate for use in asemiconductor device which is a substrate to mount semiconductor chips,an interposer for use in a semiconductor device to be manufactured byusing the clad material, as well as a manufacturing method of them.

BACKGROUND OF THE INVENTION

In recent years, along with reduction of size and weight and enhancementfor the function of electronic equipments, size reduction has beenrequired also for semiconductor packaging devices mounted therein andsmall-sized package devices have been developed. Then, a semiconductordevice of a size substantially equal with the chip size has beenproposed. Japanese Patent Laid-Open No. 74807/1998 discloses a method ofmanufacturing such a semiconductor device and a schematic view thereofis shown in FIG. 12. A semiconductor chip 101 is mounted on one side ofan interposer 100 (substrate) and connected with a wiring pattern 102 onthe substrate. Further, the wirings are conducted through via holes 103formed in the direction of the thickness of the substrate to a mountingsubstrate, and solder bumps 104 for external connection are formed tothe via holes on the side of the mounting substrate.

In the semiconductor device of the constitution as described above,conduction between both surfaces of the interposer is taken by formingthrough holes and then filling a conductive material, for example, byplating. However, steps of forming fine through holes and applyingplating therein results in a technical difficulty in that it requiresapplication of a relatively thick plating; however, this creates aproblem of increasing the cost.

This invention intends to solve the subject described above and it is asubject thereof to provide an interposer-forming clad plate for use in asemiconductor device capable of being manufactured at a reduced cost andhaving favorable characteristics, an interposer for use in asemiconductor device using the same and a manufacturing method of them.

DISCLOSURE OF THE INVENTION

An interposer-forming clad plate for use in a semiconductor deviceaccording to this invention has a feature that it is manufactured bypress-bonding a copper foil material and a nickel foil material at arolling reduction of 0.1 to 3%.

A clad plate according to this invention has a feature that it ismanufactured by press-bonding a copper foil material having nickelplating on one or both surfaces and another copper foil material or acopper foil material having a nickel plating on one surface at a rollingreduction of 0.1 to 3%.

Another feature of the clad plate according to this invention resides inthat it consists of five layers of copper/nickel/copper/nickel/copper.

The interposer for use in the semiconductor device according to thisinvention is characterized in that one of the clad plates describedabove is selectively etched to form connection bumps with asemiconductor chip and wiring layers, the semiconductor chip and thewiring layer are connected through the semiconductor chip connectionbumps by using anisotropically conductive adhesives and conduction inthe direction of the thickness of the interposer is taken by way of acolumnar conductor formed by etching.

A method of manufacturing an interposer for use in a semiconductordevice according to this invention is characterized by laminating acopper foil material forming a conductor layer or the like, a nickelfoil material or nickel plating forming an etching stop layer andpress-bonding them at a rolling reduction of 0.1 to 3% to form a cladplate for forming an interposer for use in a semiconductor device,selectively etching the clad plate to form a columnar conductor, formingan insulation layer on a copper foil material forming a wiring layer,and forming semiconductor chip connection bumps and a wiring layer tothe clad plate on the side opposite to the columnar conductor formingsurface.

A method of manufacturing a clad plate according to this invention ischaracterized by forming a clad plate by previously applying anactivating treatment to a bonding surface of a copper foil and a nickelfoil or nickel plating in a vacuum vessel, then laminating the copperfoil and, the nickel foil or the nickel plating and cold press-bondingthem at 0.1 to 3% rolling reduction in which the activating treatment isconducted <1> in an inert gas atmosphere at an extremely low pressure of1×10 to 1×10 Pa, <2> using the nickel plated copper foil material andthe copper foil material as one electrode A having the bonding surfacesgrounded to the earth, respectively, and conducting glow discharge byapplying an AC current at 1 to 50 MHz between it and the other electrodeB supported insulatively and <4> applying sputter etching, <3> with thearea of the electrode exposed in plasmas caused by the glow dischargebeing ⅓ or less of the electrode B.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory view for the steps in a method of manufacturingan interposer for use in a semiconductor device according to oneembodiment of this invention.

FIG. 2 is an explanatory view for the steps in a method of manufacturingan interposer for use in a semiconductor device according to oneembodiment of this invention.

FIG. 3 is an explanatory view for the steps in a method of manufacturingan interposer for use in a semiconductor device according to oneembodiment of this invention.

FIG. 4 is an explanatory view for the steps in a method of manufacturingan interposer for use in a semiconductor device according to oneembodiment of this invention.

FIG. 5 is an explanatory view for the steps in a method of manufacturingan interposer for use in a semiconductor device according to oneembodiment of this invention.

FIG. 6 is an explanatory view for the steps in a method of manufacturingan interposer for use in a semiconductor device according to oneembodiment of this invention.

FIG. 7 is an explanatory view for the steps in a method of manufacturingan interposer for use in a semiconductor device according to oneembodiment of this invention.

FIG. 8 is an explanatory view for the steps in a method of manufacturingan interposer for use in a semiconductor device according to oneembodiment of this invention.

FIG. 9 is an explanatory view for the steps in a method of manufacturingan interposer for use in a semiconductor device according to oneembodiment of this invention.

FIG. 10 is an explanatory view for the steps in a method ofmanufacturing an interposer for use in a semiconductor device accordingto one embodiment of this invention.

FIG. 11 is a cross sectional front elevational view of an apparatus formanufacturing the clad plate.

FIG. 12 is a cross sectional view of an existent interposer for use in asemiconductor device.

BEST MODE FOR CARRYING OUT THE INVENTION

This invention is to be explained concretely with reference to oneembodiment shown in FIG. 1 to FIG. 10. At first, the structure of asemiconductor device according to one embodiment of this invention is tobe explained with reference to FIG. 10.

As illustrated, etching stopper layers 11 and 12 (suitably with athickness of 0.1 to 3 mm) are bonded on both surfaces of a wiring layer10 comprising a copper foil (suitably with a thickness of 10 to 100 mm).A connection bump 18 (suitably with a thickness of 10 to 100 mm) for asemiconductor chip is formed at the top end of the wiring layer 10 onthe side of mounting the semiconductor chip 1. Further, an insulativeresin 13 is formed to the wiring layer on the side of the mountingsubstrate and conducted with the mounting surface is taken by way of acolumnar conductor 17 (suitably with a thickness of 10 to 100 mm) andsolder bumps 2 are formed on the mounting surface.

Then, explanation is to be made to a method of manufacturing aninterposer for use in a semiconductor device described above. At first,nickel plating 20 and 21 as etching stopper layers 11 and 12 are appliedon both surfaces of a copper foil 19 (suitably with a thickness of 10 to100 mm) to form an internal conductor layer 10 upon manufacturing theinterposer for use in the semiconductor device to manufacture a nickelplated copper foil material 22 (refer to FIG. 1).

Then, the nickel-plated copper foil material 22 is wound around adelivery reel 23 in a clad plate manufacturing apparatus shown in FIG.11. Further, a copper foil material 24 as a columnar contactor 17 iswound around a delivery reel 25. The nickel-plated copper foil material22 and the copper foil material 24 are delivered simultaneously from thedelivery reels 23 and 25 and a portion thereof is wound around electroderolls 27 and 28 protruded in an etching chamber 26 and sputter etchingis applied to activate in the etching chamber 26.

In the case, the activating treatment is applied as disclosed previouslyby the present applicant in Japanese Patent Laid-Open No. No.224184/1989 <1> in an inert gas atmosphere at an extremely low pressureof 1×10¹ to 1×10⁻² Pa, <2> using the nickel plated copper foil material22 and the copper foil material 24 as one electrode A having the bondingsurfaces grounded to the earth, respectively, and conducting glowdischarge by applying an AC current at 1 to 50 MHz between it and theother electrode B supported insulatively and <4> applying sputteretching, <3> with the area of the electrode exposed in plasmas caused bythe glow discharge being ⅓ or less of the electrode B.

Subsequently, they are cold press-bonded by a rolling unit 30 disposedin the vacuum vessel 29 and an interposer-forming clad plate 31 having athree layered structure for use in a semiconductor device is woundaround a delivery roll 32.

Then, the interposer-forming clad plate 31 for use in the semiconductordevice having the three layered structure is again wound around thedelivery roll 23. Further, a copper foil 33 (refer to FIG. 1) as aconnection bump 18 is wound around the delivery reel 25. The clad plate31 and the copper foil material 33 are unwound from the delivery reels23 and 25 and a portion thereof is wound around the electrode rolls 27and 28 protruded in the etching chamber 26 and applied with andactivated by sputter etching treatment in the etching chamber 26.

Also in this case, the activating treatment is applied <1> in an inertgas atmosphere at an extremely low pressure of 1×10¹ to 1×10⁻² pa, <2>using the nickel plated copper foil material 22 and the copper foilmaterial 24 as one electrode A having the bonding surfaces grounded tothe earth, respectively, and conducting glow discharge by applying an ACcurrent at 1 to 50 MHz between it and other electrode B supportedinsulatively and <4> applying sputter etching, <3> with the area of theelectrode exposed in plasmas caused by the glow discharge being ⅓ orless of the electrode B to manufacture a clad plate 34 for use in thesemiconductor device having a five layered structure.

In the foregoings, explanation has been made to an example ofpress-bonding a material formed by previously nickel plating on a copperfoil material, a material formed by press-bonding a nickel foil to acopper foil material by using the apparatus described above may also beused instead of the nickel plating.

Further, by repeating the press-bonding using the apparatus describedabove, a multi-layered clad layer can be manufactured in which a copperlayer is disposed to the surface and the rearface layers and the nickellayer is interposed as the intermediate layer in the order ofcopper/nickel/copper/nickel/copper.

Further, when three or more sets of delivery reels are disposed, copperfoil material or nickel foil material are disposed to the reels and foilmaterials are simultaneously supplied from the three or more reels, aclad plate of a multi-layered structure can be manufactured bypress-bonding only once.

After cutting the interposer-forming clad plate 34 for use in thesemiconductor device into a desired size, an interposer for use in thesemiconductor is manufactured by way of the following steps to beexplained with reference to FIG. 2 to FIG. 9. At first, as shown in FIG.2, after forming a photoresist film 35 on the surface of the copper foil24, it is exposed and developed.

Then, as shown in FIG. 3, the copper foil material 24 is etchedselectively and the copper foil 24 is removed leaving a columnarconductor 17. As an etching solution, sulfuric acid+aqueous hydrogenperoxide or ammonium persulfate liquid is used preferably.

Then, as shown in FIG. 4, the nickel layer 20 is removed by selectiveetching. As the etching liquid, it is desirable to use a commerciallyavailable Ni etching liquid (for example, Merstrip N-950, manufacturedby Mertechs Co.) is used preferably.

Then, as shown in FIG. 5, an insulative resin 39 is coated. As theinsulative resin 39, use of an epoxy or polyimide resin is desirable.

Then, as shown in FIG. 6, polishing is applied to make the surface ofthe resin 39 uniform. In this case, the head of the columnar conductor17 is exposed to the surface. Instead of the polishing, it is possibleto chemically remove the resin on the columnar conductor to exposer thehead.

Further, as shown in FIG. 7, the copper foil material 33 is etchedselectively to remove the copper foil material 33 leaving the columnarconductor 18. As the etching liquid, it is preferred to use, forexample, sulfuric acid+aqueous hydrogen peroxide or ammonium persulfateliquid.

Then, as shown in FIG. 8, the nickel layer 21 is removed. As the etchingliquid, it is preferred to use a commercially available Ni etchingliquid (for example Merstrip N-950, manufactured by Mertechs Co.).

Then, as shown in FIG. 9, a photoresist film 37 is formed on the surfaceof the copper foil material and exposed and developed to etch the copperfoil 19 by using, for example, ferric chloride or sulfuric acid+aqueoushydrogen peroxide. Thus the wiring layer is formed.

As shown in FIG. 10, a semiconductor chip 1 is connected to the surfaceof a wiring layer by use of anisotropically conductive adhesives 4containing conductive particles 3. Further, a solder bump 2 is formed ata position corresponding to the columnar conductor 17 on the side of themounting substrate.

Industrial Applicability

As has been explained above, in the interposer-forming clad plate foruse in the semiconductor device according to this invention, the copperfoil material and the nickel foil material are press-bonded under a lowrolling reduction of 0.1 to 3%, or the copper foil material having anickel plating on one or both surfaces and other copper foil material orother copper foil material having a nickel plating on one or bothsurfaces in a laminated state are press-bonded at a low rollingreduction of 0.1 to 3%. Accordingly, the planarity at the bondingboundary can be maintained by suppressing the stress at the bondingboundary, and no alloyed metal is formed at the boundary since heattreatment for restoration of workability is no more necessary, it ispossible to manufacture the interposer-forming clad plate for use in thesemiconductor device of excellent selective etching property.

In the interposer for use in the semiconductor device according to thisinvention, since the interposer-forming clad plate for use in thesemiconductor device as described above is etched selectively, to formerconnection bumps with semiconductor chip and the wiring layer andconduction of the interposer along the direction of the thickness istaken by way of the columnar conductor formed by etching, the interposerfor use in the semiconductor device capable of coping with the smallsized semiconductor device can be manufactured efficiently at a reducedcost. Further, since connection between the semiconductor chip and thewiring layer is conducted through the semiconductor chip connectionbumps by using anisotropically conductive adhesives containingconductive particles, there is no requirement for forming the bump onthe semiconductor chip and the cost for the semiconductor device can bereduced. In the method of manufacturing the interposer-forming cladplate for use in the semiconductor device according to this invention,since the clad plate is formed by previously applying the activatingtreatment to the bonded surfaces of the copper foil and the nickelplating in the vacuum vessel, then laminating the copper foil and thenickel plating and cold press-bonding them at a rolling reduction of 0.1to 3% in a vacuum vessel, the planarity at the bonded boundary can bemaintained by suppressing the stress at the bonding boundary, and sincethe heat treatment for the restoration of the workability is no morerequired and no alloy layer is formed at the boundary, theinterposer-forming clad plate for use in the semiconductor device ofexcellent selective etching property can be manufactured.

In the method of manufacturing the interposer-forming clad plate for usein the semiconductor device according to this invention, since the cladplate is formed by previously applying the activating treatment to thebonded surfaces of the copper foil and the nickel plating in the vacuumvessel, then laminating the copper foil and the nickel plating and coldpress-bonding them at a rolling reduction of 0.1 to 3% in a vacuumvessel, the planarity at the bonded boundary can be maintained bysuppressing the stress at the bonding boundary, and since the heattreatment for the restoration of the workability is no more required andno alloy layer is formed at the boundary, the interposer-forming cladplate for use in the semiconductor device of excellent selective etchingproperty can be manufactured.

1. An interposer-forming clad plate for use in a semiconductor devicemanufactured by press-bonding a copper foil material and a nickel foilmaterial at a rolling reduction of 0.1 to 3%, wherein the clad platecomprises five layers of copper/nickel/copper/nickel/copper.
 2. A methodof manufacturing an interposer-forming clad layer for use in asemiconductor device as defined in claim 1 wherein theinterposer-forming clad plate for use in the semiconductor device isformed by previously applying an activating treatment to the bondedsurfaces of the copper foil and the nickel foil or nickel plating in avacuum vessel and them laminating the copper foil and the nickel foilmaterial or nickel plating and cold press-bonding them at a rollingreduction of 0.1 to 3% in which the activating treatment is applied inan inert gas atmosphere at an extremely low pressure of 1×10¹ to 1×10⁻²Pa, using the nickel plated copper foil material and the copper foilmaterial as one electrode A having the bonding surfaces grounded to theearth, respectively, and conducting glow discharge by applying an ACcurrent at 1 to 50 MHz between it and the other electrode B supportedinsulatively and applying sputter etching, with the area of theelectrode exposed in plasmas caused by the glow discharge being ⅓ orless of the electrode B.
 3. An interposer for use in a semiconductordevice in which a clad plate as defined in claim 1 is etched selectivelyto form connecting bumps with a semiconductor chip and a wiring layer,the semiconductor chip and the wiring layer are connected by way of thesemiconductor chip connection bumps using anisotropically conductiveadhesives and conduction of the interposer in the direction of thethickness is taken by way of a columnar conductor formed by etching. 4.An interposer for use in a semiconductor device in which a clad plate isetched selectively to form connecting bumps with a semiconductor chipand a wiring layer, the semiconductor chip and the wiring layer areconnected by way of the semiconductor chip connection bumps usinganiso-tropically conductive adhesives and conduction of the interposerin the direction of the thickness is taken by way of a columnarconductor formed by etching, wherein said clad plate is made bypress-bonding a copper foil material and a nickel foil material at arolling reduction of 0.1 to 3%.
 5. A method of manufacturing aninterposer for use in a semiconductor device, which comprises laminatinga copper foil material to form a conductor layer and a nickel foil ornickel plating to form an etching stop layer, press-bonding them at arolling reduction of 0.1 to 3% to form an interposer-forming clad layerfor use in a semiconductor device, selectively etching the clad plate toform a columnar conductor, forming an insulation layer on the copperfoil material to form a wiring layer, and forming a semiconductor chipconnection bumps and the wiring layer to the clad plate on the sideopposite to the surface for forming the columnar conductor.
 6. Aninterposer-forming clad plate for use in a semiconductor devicemanufactured by press-bonding a copper foil material having nickelplating on one surface or both surfaces and other copper foil materialor a copper foil material having nickel plating on one surface at arolling reduction of 0.1 to 3%, wherein the clad plate comprises fivelayers of copper/nickel/copper/nickel/copper.
 7. A method ofmanufacturing an interposer-forming clad layer for use in asemiconductor device as defined in claim 6, wherein theinterposer-forming clad plate for use in the semiconductor device isformed by previously applying an activating treatment to the bondedsurfaces of the copper foil and the nickel foil or nickel plating in avacuum vessel and them laminating the copper foil and the nickel foilmaterial or nickel plating and cold press-bonding them at a rollingreduction of 0.1 to 3% in which the activating treatment is applied inan inert gas atmosphere at an extremely low pressure of 1×10¹ to 1×10⁻²Pa, using the nickel plated copper foil material and the copper foilmaterial as one electrode A having the bonding surfaces grounded to theearth, respectively, and conducting glow discharge by applying an ACcurrent at 1 to 50 MHz between it and the other electrode B supportedinsulatively and applying sputter etching, with the area of theelectrode exposed in plasmas caused by the glow discharge being ⅓ orless of the electrode B.
 8. An interposer for use in a semiconductordevice in which a clad plate as defined in claim 6, is etchedselectively to form connecting bumps with a semiconductor chip and awiring layer, the semiconductor chip and the wiring layer are connectedby way of the semiconductor chip connection bumps using anisotropicallyconductive adhesives and conduction of the interposer in the directionof the thickness is taken by way of a columnar conductor formed byetching.
 9. An interposer for use in a semiconductor device in which aclad plate is etched selectively to form connecting bumps with asemiconductor chip and a wiring layer, the semiconductor chip and thewiring layer are connected by way of the semiconductor chip connectionbumps using aniso-tropically conductive adhesives and conduction of theinterposer in the direction of the thickness is taken by way of acolumnar conductor formed by etching, wherein said clad plate ismanufactured by press-bonding a copper foil material having nickelplating on one surface or both surfaces and other copper foil materialor a copper foil material having nickel plating on one surface at arolling reduction of 0.1 to 3%.